Liver Cell Injury Research Articles

Ultrastructural sequences during liver iron overload in genetic hemochromatosis

Background/Aims: The pathway through which iron contributes to liver cell damage and cirrhosis in genetic hemochromatosis is not clear. The objective of the present study was to describe the ultrastructural changes in liver biopsies of patients in various stages of this condition and to correlate these with clinical, histopathological and biochemical data. Methods: Liver biopsies from 20 patients with genetic hemochromatosis were examined by transmission electron microscopy. The use of unstained thin (60 nm) sections facilitated the identification and localization of the electron-opaque compounds of ferritin and hemosiderin in various liver cells. Stained thin sections permitted evaluation of the concomitant subcellular damage and collagen deposition. The ultrastructural observations were corroborated with the histopathological findings and biochemical data. Results: All patients had liver iron overload, which was classified as mild, moderate or severe. In the stage of mild overload (hepatic iron concentration HIC 93.5±23.3 μmol/g and hepatic iron index HII 2.3±0.7), cytosolic ferritin and scarce pericanalicular lysosomes (siderosomes) were seen in periportal hepatocytes (acinar zone 1), without evidence of organelle damage, and in the absence of sinusoidal cell siderosis. In moderate overload (HIC 190.8± 41.5 μmol/g and HII 4.3±1.9), ferritin was identified in hepatocytes of all acinar zones, and the pericanalicular siderosomes were abundant, especially in acinar zone 1. Single hepatocytes showed organelle damage and occasional sinusoidal cells showed siderosis. In severe overload (HIC 308±49.0 μmol/g and HII 7.5±1.7), hepatocytes of all acinar zones were-filled with large, hemosiderin-containing siderosomes, and changes in mitochondria, smooth and rough endoplasmic reticulum and nuclei were conspicuous. Marked sinusoidal cell siderosis and collagen deposition were observed predominantly in this stage. Conclusions: Electron microscopy has shown that during the long, latent stage of “compensated” genetic hemochromatosis, hepatocytes display only minimal subcellular changes, other than iron overload. “Decompensated” overload, characterized by extensive subcellular pathology and focal necrosis, is reached when 1) the hepatocytic siderosis is generalized (i.e. beyond pericanalicular polarization of siderosomes in hepatocytes, and beyond zone 1 in the acinus); and 2) there is evidence of massive siderosis of sinusoidal cells. These findings support the concept of a critical level of hepatic iron concentration beyond which organelle damage is conspicuous and liver cell injury may become irreversible.

Fas system and apoptosis in viral hepatitis

Hepatitis C virus (HCV) and hepatitis B virus (HBV) are the major causative agents of chronic liver disease. However, the mechanisms responsible for liver cell injury remain to be clarified. Playing crucial roles in the clearance of viral infection are cytotoxic T lymphocytes. Recently, it has been demonstrated that perforin- and Fas-based mechanisms account for all T cell-mediated cytotoxicity. Therefore, we examined the correlation between liver cell damage and the Fas system in the liver of patients with chronic hepatitis C. Fas is a cell surface protein that mediates apoptosis with treatment of the Fas ligand or the anti-Fas antibody. To investigate the role of Fas in type C hepatitis, we examined the correlation between liver cell damage and Fas expression. Fas expression was found mainly in the cytoplasm of hepatocytes and these positive cells were found particularly among infiltrating lymphocytes. A high prevalence of Fas expression was shown in liver tissue with more severe inflammation. The Fas system-mediated death signal requires the interaction of Fas ligand with Fas on target cells. We isolated a 1.9 kb cDNA clone for the human Fas ligand and examined the expression of the Fas ligand in liver-infiltrating mononuclear cells obtained from patients with chronic hepatitis C. The open reading frame encodes 281 amino acids. Next, we examined the expression of the Fas ligand in liver-infiltrating mononuclear cells obtained from patients with chronic hepatitis C. The amplified products (231 bp) derived from Fas ligand transcripts were detected in liver-infiltrating mononuclear cells, whereas no signal was observed in liver tissues. In HCV infection, Fas expression in hepatocytes is up-regulated in accordance with the severity of liver inflammation. When HCV-specific T cells migrate into hepatocytes and recognize the viral antigen via the T cell receptor, they become activated and express Fas ligand that can transduce the apoptotic death signal to Fas-bearing hepatocytes. Thus, the Fas system plays an important role in liver cell injury by HCV infection.

Acute liver injury related to the use of niperotidine

Background/Aims: H 2-receptor antagonists are widely used for the therapy of peptic disease, since they ensure a protracted and intense inhibition of gastric acidity. Niperotidine (piperonyl-ranitidine) is a new H 2 blocking agent recently proposed for clinicla use. Methods: Twenty-five cases of acute hepatitis associated with the use of niperotidine were reported in Italy between March and August 1995. Intercurrent viral infections, recent drug and alcohol consumption and blood transfusions were excluded as causes. Results: All patients showed an increase in the parameters of liver cell injury and the clinical symptoms of acute hepatitis. After withdrawal of the drug, all patients showed a good outcome, except one who developed a fulminant hepatitis and died from digestive tract bleeding. Conclusions: The absence of other causes of acute liver injury suggests that the observed liver injury may be a niperotidine-adverse reaction. Moreover, the lack of a relationship between the dose of the drug and the degree of liver damage, the variable latent period and the rarity and unpredictability of the injury are suggestive of an idiosyncratic reaction.

The isolated perfused porcine liver: assessment of viability during and after six hours of perfusion.

Isolated liver perfusion was developed for the study of liver physiology and preservation. The recent development of new perfusion devices and appropriate liver preservation solutions prompted us to reconsider liver perfusion for the specific purpose of evaluating viability in terms of biochemical changes, paying special attention to modifications in the histological ultrastructure. Twenty-two isolated pig livers were perfused with autologous blood. Arterio-portal perfusions were carried out using an extracorporeal perfusion circuit with a hollow fibre membrane oxygenator. Four groups of pig livers were studied using three different liver flushing solutions [Ringer's lactate, ELOHES, and University of Wisconsin (UW)] and two different oxygenation modalities. Liver function tests and histological studies were done. Our results revealed that a high partial oxygen pressure (PO2) level was deleterious to the ultrastructural elements of hepatocytes, in particular to the mitochondria. It was also associated with deficient metabolic performance, i.e., poor bile production and lack of aerobic metabolism. Normal blood gas values could be obtained with the use of air for liver oxygenation. Flushing of the liver with Ringer's lactate or a macromolecular solution such as ELOHES was associated with severe liver cell injuries, as reflected by a marked rise in liver enzymes and histological lesions. Satisfactory results were obtained when UW solution was used for liver harvesting. We conclude that an appropriate liver preservation solution, normal blood gas values, and normal physiological arterio-portal pressure and blood flow are essential for appropriate liver function with preservation of liver architecture and of hepatocyte ultrastructures. Total bilirubin in bile and Factor V are sensitive indicators of good liver function.

Protective effect of monoclonal antibodies to adhesion molecules on rat liver ischemia-reperfusion injury

Background. The source of reactive oxygen species in the liver remains to be elucidated. The present study was undertaken to determine whether polymorphonuclear neutrophils (PMNs) can contribute to hepatic ischemia-reperfusion injury, and pretreatment with monoclonal antibodies (mAbs)to intercellular adhesion molecule—1 (ICAM-1), lymphocyte function associated antigen—1 (LFA-1), and CD 18 could improve energy metabolism and prolong the viability of the organ. Methods. Male Wistar rats were used. Rat liver ischemia was induced by clamping blood vessels supplying median and left lateral hepatic lobes. Monoclonal antibodies to ICAM-1, LFA-1, or CD18 were injected intravenously 5 minutes before inducing ischemia. To determine the effect of mAbs on the survival rate, total hepatic ischemia was induced by clamping the hepatic artery, portal vein, and bile duct after making a portafemoral shunt. Results. Although ischemia of the liver for 90 minutes did not permit survival of the animals, pretreatment with mAbs to ICAM-1 plus LFA-1 increased the survival rate to 57%. Pretreatment with mAb to ICAM-1 failed to increase the survival rate. The number of PMNs in the liver increased continually up to 24 hours after reperfusion after 90 minutes of ischemia, and the expression of ICAM-1 was enhanced 4 hours after reperfusion. This is accompanied by a low recovery of hepatic adenosine triphosphate and, on the contrary, a marked increase in lipid peroxide in the reperfused liver. Pretreatment with mAbs suppressed the infiltration of PMNs and the elevation of lipid peroxide and enhanced the recovery of hepatic adenosine triphosphate 6, 12, or 24 hours after reperfusion. Pretreatment with mAbs also prevented the rise in serum alanine aminotransferase level after reperfusion. Conclusions. These results suggest that PMNs contribute to ischemia-reperfusion injury in the liver 4 hours and more after reperfusion, and pretreatment with mAbs to adhesion molecules is useful for the prevention of ischemic liver cell injury.

Effect of Ca2+ channel blockers, external Ca2+ and phospholipase A2 inhibitors on t-butylhydroperoxide-induced lipid peroxidation and toxicity in rat liver slices.

ObjectivesThis study was undertaken to examine the effect of oxidant on lipid peroxidation and lethal cell injury in rat liver slices.Methodst-Butylhydroperoxide (t-BHP) was employed as a model of an oxidant. The lipid peroxidation and lethal cell injury were estimated by measuring the formation of malondialdehyde (MDA) and lactate dehydrogenase (LDH) release, respectively.Resultst-BHP increased lipid peroxidation and LDH release in a dose-dependent manner over concentrations of 0.5–10mM. t-BHP-induced lipid peroxidation was completely prevented by an antioxidant, N,N-diphenyl-p-phenylenediamine (DPPD), but LDH release was partially decreased. Both t-BHP-induced lipid peroxidation and LDH release were significantly protected by iron chelator, deferoxamine, sulfhydryl reducing agent, dithiothreitol and glutathione. Ca2+ channel blockers, verapamil, diltiazem and nifedipine exerted a significant protective effect against t-BHP-induced lipid peroxidation and LDH release. By contrast, addition of external Ca2+ chelator, ethylene glycol bis(b-aminoethyl ether)-N,N-tetraacetic acid (EGTA) did not alter t-BHP-induced lipid peroxidation, whereas t-BHP-induced lethal cell injury was significantly prevented. Phospholipase A2 (PLA2) inhibitors, mepacrine and butacaine produced a partial protective effect.ConclusionsThese results suggest that t-BHP induces cell injury by lipid peroxidation-dependent and -independent mechanisms which can be partially prevented by Ca2+ channel blockers and PLA2 inhibitors.

Predominant T-helper 1 cytokine profile of hepatitis B virus nucleocapsid-specific T cells in acute self-limited hepatitis B.

The cytokine pattern secreted by T cells on viral antigen recognition is believed to exert a profound influence on both the type of disease caused by the infecting agent and the final outcome of the viral infection. To characterize the cytokine pattern associated with spontaneous resolution of acute hepatitis B, we analyzed interferon gamma (IFN-gamma), interleukin (IL)-4, and IL-5 production by a wide series of hepatitis B virus (HBV) nucleocapsid-specific T-cell lines (34 lines) and T-cell clones (71 clones) derived from the peripheral blood of 13 patients during the acute or recovery phase of hepatitis B (2 and 7 of them were studied only in the recovery or the acute phase, respectively, and 4 during both). Most T-cell lines (67%) and clones (77%) isolated during the acute phase of infection expressed a T-helper (Th) 1 cytokine profile dominated by the production of IFN-gamma. A larger proportion (74%) of T-cell lines produced several years after resolution of hepatitis was able to secrete not only IFN-gamma, but also IL-4 and IL-5 (Th0-like cells). Results indicate that the antigen-specific fraction of peripheral blood T cells in acute self-limited hepatitis B selectively secrete Th1-type eytokines, suggesting that Th1-mediated effects may contribute not only to liver cell injury, but probably also to recovery from disease and successful control of infection.

Sensitization to Fas-Mediated Apoptosis by Hepatitis C Virus Core Protein

We have characterized viral–cell interactions of hepatitis C virus (HCV) and liver cells to study the pathogenesis of HCV infection. HepG2 cells constitutively expressing HCV core protein showed apoptotic changes in response to stimulation with anti-Fas monoclonal antibody. Cells treated with the antibody showed extensive cell rounding, shrinkage, and cytoplasmic blebbing and finally detached from plates. Fragmentation of the chromatin was observed in the nucleus and DNA ladders were detected. In contrast, cells expressing HCV envelope, nonstructural proteins or normal HepG2 cells did not exhibit such Fas-mediated apoptosis. However, expression of Fas receptor was not upregulated on the surface of the cells expressing HCV core protein. Apoptotic cell death was prevented by pretreatment with a specific inhibitor of the cysteine protease CPP32, while the specific inhibitor of interleukin-1β-converting enzyme did not show the preventive effect. The results suggest (i) that intracellular expression of HCV core protein makes cells prone to apoptotic death without upregulation of surface Fas expression and (ii) that the CPP32 protease plays a part in the apoptosis effector pathway of HCV core-expressing cells. HCV core protein may have a role in immune-mediated liver cell injury.

Progressive necrosis after hepatectomy and the pathophysiology of liver failure after massive resection

Background. Mortality after hepatectomy in rats increases markedly beyond the classic 2/3 resection from which complete recovery is the rule. Because an extremely small hepatocyte population can theoretically sustain life, we hypothesize that lethal liver failure after subtotal resection could be due to progressive injury occurring in the remnant liver. The obligatory increase in portal blood through the small remnant may be central to the pathogenesis because of sinusoidal injury and Kupffer's cell activation. To test this hypothesis an experimental study in rats was undertaken to characterize liver cell injury after lethal (85%) and nonlethal (70%) hepatectomy. Methods. One hundred thirty Wistar rats were divided into three groups: control group (sham laparotomy, n = 30), 70[5] hepatectomy group (n = 50), and 85% hepatectomy group (n = 50). Five rats in each group were killed for blood and liver collections from 15 minutes to day 14 after hepatectomy. Survival, histologic characteristics, serum activities of aspartate (AST) and alanine (ALT) aminotransferases and arginase were determined; serum level of tumor necrosis factor-α (TNF-α) and plasma level of prostaglandin E 2 (PGE 2) were measured by enzyme-linked immunosorbent assay. Results. Whatever the extent of resection, hepatic injury, as demonstrated by increased serum levels of arginase, ALT, and AST, was observed. The kinetics of arginase release after hepatectomy mimicked quite well those of AST and ALT, representing a reliable marker of hepatocyte injury. A significantly higher, more prolonged blood release of enzymes was observed after 85% hepatectomy than after 70% hepatectomy. Because of a very short half-life the rise in arginase several hours after hepatectomy seems to indicate ongoing liver damage distinct from the surgical injury. Significant elevations of TNF-α were detected that were much more severe after 85% hepatectomy. PGE 2 levels that increased significantly after 70% resection remained depressed after 8% hepatectomy. Light microscopy demonstrated extensive patchy necrosis after 85% hepatectomy. Conclusions. A pattern of progressive necrosis of the remnant liver was identified with Kupffer's cell dysfunction. We hypothesize that failure of down-regulation of TNF-α production by PGE 2 could contribute to the pathophysiology of liver injury in the remnant after massive hepatectomy. These events may be initiated in part by the dramatic increase of portal flow through a too small remaining liver, and a pathologic mechanism may be amenable to pharmacologic manipulation.

Modulating Role of Endogenous Reduced Glutathione in Tert-Butyl Hydroperoxide-Induced Cell Injury in Isolated Rat Hepatocytes

The role of endogenous reduced glutathione (GSH) in tert-butyl hydroperoxide (TBHP)-induced cell injury was examined in isolated rat hepatocytes. When liver cell injury was estimated from release of transaminases from hepatocytes into the incubation medium, cell injury in hepatocytes (2 × 10 6 cells/ml) incubated in Hanks' balanced salt solution (pH 7.2) containing 1.0 mM TBHP at 37°C was potentiated with enhanced lipid peroxidation by prior depletion of intracellular GSH which was induced by diethylmaleate, a GSH depletor. GSH-depleted hepatocytes were incubated with γ-glutamylcysteinylethyl ester ( γ-ECOEt), which is known to be converted to GSH via glutathione synthetase after its hydrolysis by esterase, at concentrations of 1.0 to 10 mM in order to replenish intracellular GSH. Although TBHP-induced cell injury and lipid peroxidation were enhanced in GSH-depleted hepatocytes, these enhancements were prevented with the consumption of intracellular GSH in GSH-depleted hepatocytes pretreated with 5.0 mM γ-ECOEt. These preventive effects were observed at any time point during the TBHP treatment over a 60 min period and depended on the concentration of γ-ECOEt used. But, no preventive effect was found in GSH-depleted hepatocytes pretreated with 5.0 mM GSH. No prevention of the potentiation of TBHP-induced cell injury found in GSH-depleted hepatocytes occurred in GSH-depleted hepatocytes pretreated with both 5.0 mM γ-ECOEt and 250 μM bis-( p-nitrophenyl)phosphate, a nonspecific esterase inhibitor. γ-ECOEt treatment caused an increase in intracellular GSH content in GSH-depleted hepatocytes, while treatments of both γ-ECOEt and the esterase inhibitor caused no increase in intracellular GSH content in the cells. These results indicate that endogenous GSH modulates TBHP-induced cell injury and lipid peroxidation in isolated rat hepatocytes. The present results suggest that endogenous GSH should play a critical role in TBHP-induced cell injury in isolated rat hepatocytes and that in rat hepatocytes treated with TBHP, enhanced lipid peroxidation with the consumption of intracellular GSH could be associated with the initiation of cell injury.

Intermittent Anoxia Reduces Oxygen Free Radicals Formation During Reoxygenation in Rat Hepatocytes

The sensitivity of liver cells to anoxia is a major problem afflicting liver preservation and transplantation. Intermittent ischemia has been proposed to reduce reperfusion injury. The aim of the study was to assess oxygen free radical formation and cell injury during continuous or intermittent anoxia/reoxygenation in rat hepatocytes. Anion superoxide was measured by lucigenin-enhanced chemiluminescence and cell damage by LDH release and trypan blue uptake. During anoxia, superoxide generation dropped to background level in both groups; trypan blue uptake and LDH release, which increased progressively, were significantly greater in hepatocytes exposed to continuous compared to intermittent anoxia. During reoxygenation, a massive generation of superoxide anion formation, followed by a sharp increase in LDH release, was observed in both groups. However, both oxyradical generation and cell injury were significantly greater in cells exposed to continuous compared to intermittent anoxia. The data, showing that intermittent oxygen deprivation reduce liver cell injury and oxygen free radical formation determined by anoxia/reoxygenation, suggest a novel possible approach to the reduction of reperfusion injury.

The epidemiology of hepatocellular carcinoma in patients with acute intermittent porphyria.

To describe the epidemiology, pathogenesis and clinical features of hepatocellular carcinoma (HCC) in patients with acute intermittent porphyria (AIP). A retrospective population-based mortality study. All inhabitants who died between 1978-1990 (2122) including 33 with AIP, in two municipalities in northern Sweden with a high prevalence of AIP. Death certificates and hospital records were examined. Histological re-examination of paraffin-embedded specimens from patients with HCC was performed and hepatitis B virus content analysed. HCC was found in 27% of patients with AIP versus 0.2% of the deceased non-AIP subjects, P < 0.0001. HCC was more common in women (men:women 1:2) and in manifest AIP (manifest: latent 2:1). Liver cirrhosis was more common in AIP patients (12%), especially in women, compared with controls (0.5%), P < 0.0001. AIP patients seem to have an increased risk of developing HCC. This tumour is more common in patients with manifest AIP and in women, a reversal of the usually reported gender ratio for HCC. No cause for developing HCC other than AIP was found. The pathogenesis may be explained by abnormalities in porphyrin metabolism and by intrinsic production of mutagenic substances, resulting in a condition of systemic overload of oxidative stress, enhancing mutation rate and liver cell injury. Liver cirrhosis appears to be more common in AIP patients and may be a preliminary stage to HCC. All AIP gene carriers aged > or = 55 should be screened for HCC.

Differential induction of carcinogen metabolizing enzymes in a transgenic mouse model of fulminant hepatitis.

The objective of this work is to examine the possible modulation of carcinogen metabolism (activation by cytochrome P450s and detoxification by conjugation via glutathione S-transferases [GST]) in relation to hepatitis B virus (HBV)-associated liver injury. In HBV transgenic mouse lineage 107.5, the hepatitis B surface antigen (HBsAg) is expressed at noncytopathic concentrations but after injection of an HBsAg-specific, major histocompatibility complex (MHC) class I restricted cytotoxic T-lymphocyte (CTL) clone, the mice develop a severe acute necroinflammatory liver disease that reaches maximum severity within 3 days and gradually subsides during the next 2 to 3 weeks. In this model, using immunohistochemical analysis, we observed an increase of P450s (CYP1A and 2A5), both involved in aflatoxin B1, metabolism, but minor changes or no changes for others (2B, 2C, 2E, 3A). There was a fivefold decrease in the total liver P450 microsomal content 3 days' post-CTL injection with the result that the relative proportion of CYP2A5 and 1A compared with other P450s is increased. Individual microsomal P450 enzyme contents estimated by Western blotting; Northern blot analysis of liver CYP messenger RNA (mRNA) levels as well as in vitro metabolism of specific substrates for different P450 isoenzymes were consistent with the immunohistochemical data. Immunohistochemical staining with antibodies to cytosolic pi class GST was increased 1 and 3 days postinjection followed by a progressive decrease at later time points (the same phenomenon was observed to a lesser extent for GST alpha). The activity of hepatic cytosols toward substrates specific for different subclasses of GST (mu, pi, alpha) showed that while GST mu was not changed in the CTL-injected HBV transgenic mice, GST pi and, to a lesser extent, alpha were increased as compared with controls. These results suggest that liver cell injury induced by a process of acute fulminant-like hepatitis can lead to the induction of some carcinogen metabolizing enzymes notably, Cyp 1A, 2A5 and GST pi in the mouse.

Differential induction of carcinogen metabolizing enzymes in a transgenic mouse model of fulminant hepatitis

The objective of this work is to examine the possible modulation of carcinogen metabolism (activation by cytochrome P450s and detoxification by conjugation via glutathione S-transferases [GST]) in relation to hepatitis B virus (HBV)-associated liver injury. In HBV transgenic mouse lineage 107.5, the hepatitis B surface antigen (HBsAg) is expressed at noncytopathic concentrations but after injection of an HBsAg-specific, major histocompatibility complex (MHC) class I restricted cytotoxic T-lymphocyte (CTL) clone, the mice develop a severe acute necroinflammatory liver disease that reaches maximum severity within 3 days and gradually subsides during the next 2 to 3 weeks. In this model, using immunohistochemical analysis, we observed an increase of P450s (CYP1A and 2A5), both involved in aflatoxin B1, metabolism, but minor changes or no changes for others (2B, 2C, 2E, 3A). There was a fivefold decrease in the total liver P450 microsomal content 3 days' post-CTL injection with the result that the relative proportion of CYP2A5 and 1A compared with other P450s is increased. Individual microsomal P450 enzyme contents estimated by Western blotting; Northern blot analysis of liver CYP messenger RNA (mRNA) levels as well as in vitro metabolism of specific substrates for different P450 isoenzymes were consistent with the immunohistochemical data. Immunohistochemical staining with antibodies to cytosolic pi class GST was increased 1 and 3 days postinjection followed by a progressive decrease at later time points (the same phenomenon was observed to a lesser extent for GST alpha). The activity of hepatic cytosols toward substrates specific for different subclasses of GST (mu, pi, alpha) showed that while GST mu was not changed in the CTL-injected HBV transgenic mice, GST pi and, to a lesser extent, alpha were increased as compared with controls. These results suggest that liver cell injury induced by a process of acute fulminant-like hepatitis can lead to the induction of some carcinogen metabolizing enzymes notably, Cyp 1A, 2A5 and GST pi in the mouse. (Hepatology 1996 Sep;24(3):649-56)

Therapeutic modulation of free radical-mediated reperfusion injury of the liver and its surgical implications.

It is well known that ischemia causes functional and structural damage to liver cells, and that the status of energy metabolism provides an important means of assessing the functional viability of the ischemic organ. However, the specific sequence leading to ischemic liver cell injury is not yet fully understood; therefore, it is clinically and pathophysiologically important to elucidate the mechanism of cellular injury during hepatic ischemia and subsequent reperfusion. Whereas the conventional view attributes this injury process to the ischemia itself, recent studies have demonstrated that a variable but often substantial proportion of this injury is caused by reactive oxygen metabolites that are generated at the time of reperfusion. This article presents an outline of the mechanism of cellular injury caused during hepatic ischemia and subsequent reperfusion resulting from certain types of surgery, with special reference to the xanthine-xanthine oxidase system and the activation of neutrophils and macrophages.

Cholestase aiguë inaugurale d'une maladie de Kawasaki

Hepatic dysfunction with mild obstructive jaundice occurs occasionally in Kawasaki disease. Acute episode of cholestasis as a presenting symptom has never been reported. A 14 year-old-boy was admitted with fever and cholestasis. He subsequently developed the classical manifestations of Kawasaki disease. No signs of liver cell injury or hepatic failure were present. Bacteriological cultures and seroimmunologic markers for viral infection remained negative. There was no ultrasonic abnormality of bile ducts. The child was given intravenous gamma globulins and salicylate. The outcome was favourable without any cardiovascular complications. A persistent febrile cholestasis of unknown etiology should evoke the diagnosis of Kawasaki disease.

Hepatocellular Injury in Hepatitis B and C Virus Infections

Most of the liver cell injury in hepatitis B and C infections is likely to be immune-mediated. Variation in the pathogenesis of these infections likely is contributed by a variety of host and virus factors. Host factors include the human leukocyte antigen (HLA) haplotype as well as the ability of the host to both recognize antigen on virus-infected cells and to receive the appropriate co-stimulatory signals in a timely fashion during infection. Virus factors include the genetic variation, direct cytopathic effects, and the alteration of infected hepatocytes to cytotoxic cytokines. The lack of suitable tissue culture systems and animal models limits the ability to understand the pathogenesis fully but provides challenges for their future development so that the basis for liver cell damage can be elucidated and approaches for therapeutic intervention can be achieved.

Long-term ursodeoxycholic acid treatment of cholestatic liver diseases in childhood--clinical and biochemical effects

In adults with chronic cholestatic liver disorders, controlled studies have shown a reduction of clinical, biochemical and possibly histological parameters during long-term medication with ursodeoxycholic acid (UDCA). It is not yet clear, however, whether similar effects can be achieved in children. Therefore, we retrospectively evaluated the use of UDCA in typical liver diseases of childhood. 20 children were treated for at least 6 months (age at start of therapy 5-87, median 24 months; diagnosis: biliary atresia n = 10, Alagille's syndrome n = 4, intrahepatic biliary hypoplasia n = 3, Byler disease n = 3). Pruritus, liver cell injury, cholestasis, synthetic liver function and weight and height for age before medication with UDCA (7-26, mean 13 mg/kg BW/d) was compared to values after 3, 6, 12, 18 and 24 months of therapy, with special attention towards possible adverse effects. No adverse effects of UDCA necessitating modification of therapy were encountered. During the first year of medication, weight for age improved in 15 patients, but pruritus in only four. During UDCA treatment, GIDH and gamma GT decreased significantly. GOT and GPT declined in the majority of patients. No significant changes of bilirubin and parameters of liver synthesis were seen. Long-term medication with UDCA appears to be safe in children. Thus, controlled studies of UDCA medication in children are justified, and are urgently needed to further investigate the prognostic significance of the positive effects of UDCA identified in this retrospective analysis.

Protection in the late stages of paracetamol-induced liver cell injury with fructose, cyclosporin A and trifluoperazine

A fixed combination of the three components, fructose, cyclosporin A and trifluoperazine (FCAT), was found to protect in the late stage of paracetamol-induced liver cell injury both in vivo and in an in vivo/in vitro system. Rats pre-induced with phenobarbitone were given a paracetamol dose of 1 g/kg i.p. The combination of FCAT was given orally 3 h or 3 and 8 h after paracetamol and was able to afford protection as seen by measurement of plasma alanine transaminase (ALT) levels at 24 h. In the in vivo/in vitro system, rats pre-induced with phenobarbitone were dosed with paracetamol 1 g/kg i.p. to initiate injury and liver slices were then taken 3, 4 and 5 h later. The liver slices were then incubated for up to 18 h with the protective agents (FCAT) and the progression of injury followed. Injury was assessed by lactate dehydrogenase (LDH) leakage into the medium and potassium content of the slices. FCAT significantly reduced the injury even as assessed after 5 h in vivo initiation and 18 h progression in vitro. Mitochondrial membrane potential was also maintained in the FCAT-treated liver slices from paracetamol-treated rats as seen by the ability to maintain a gradient of triphenyl methyl phosphonium (TPMP +) between the cell and external medium. All three compounds are required for protection, indicating that more than one event is critical to the survival of the cell and each target point needs to be protected for effective long-term cell survival. The in vivo/in vitro system has been found to give a better comparability to the in vivo situation than injury models that take 6 h or less (Beales and McLean, 1995, in press).

Veränderungen von Serumenzymen, Lactat‐, und Hämoglobinkonzentrationen im Blut junger Trabrennpferde durch Trainingsbelastung

Until the age of about 2 years, trotters normally grow up on pasture without any kind of training. In the stud farm Lindenhof (Templin, Germany), however, these first 2 years are used for a special fitness training for the young animals: 2-3 times a week, a group of the yearlings is forced to run a distance of about 1700 m on a track at an average speed of up to 10 m/s. Until now, little was known about changes of blood parameters which may occur during such special exercise. This study therefore investigated the activity of selected serum enzymes (aspartate-amino-transferase (AST), alanine-amino-transferase (ALT), gamma-glutamyl-transferase (gamma-GT), lactic dehydrogenase (LDH), alkaline phosphatase (AP), creatine kinase (CK)) and the variations of hematocrit, hemoglobin, lactate, protein, and urea concentration before and after exercise. Except for activity of AP and CK and concentration of urea, all parameters showed a distinct increase after exercise. In particular, the rise in lactic-acid concentration with values up to 23.08 mmol/l was remarkable, however, none of the parameters reached a pathological level. It is therefore concluded that exercise for young trotters over a medium distance-even at high speed-does not cause any injury of myocardium, skeletal muscles or liver cells.